The present invention has essentially for a subject matter a lock with a double locking mechanism.
It is also directed to a safe or more particularly a bank compartment equipped with such a lock.
It is known that compartments rented by banks to private persons, who can thus store therein valuables of any kind, generally include a lock with a double locking mechanism, namely, a first mechanism actuated by a first key which is in the possession of the bank and which, after being actuated, authorizes the opening of the compartment by the renter or holder of the chest by means of a second key acting upon a second locking mechanism which actuates the bolt or bolts.
Usually the first locking mechanism is essentially constituted by a set of tumblers movable by the first key, whereas the second locking mechanism operated by the second key is essentially constituted by at least one bolt associated with a releasable fingered bolt-retaining means adapted to co-operate with the tumblers to allow retracting the bolt and therefore opening the lock only after the first key has moved the tumblers to an appropriate position with respect to the releasable bolt-retainer.
Now, as is readily understood, it would be interesting, in a lock of this kind, to provide for additional means of control from a distance playing the same role as the said first key. In other words, when the renter, of the compartment desires to have access to his compartment, the bank employee can, without moving from his place, act for example upon electric control means to operate the first locking mechanism and thus allow the user of the compartment to open it by means of his own key.
To allow such control from a distance, it is readily understood that, in a lock of the kind referred to above, i.e., including a simple set of tumblers for the first locking mechanism, a special mechanism must be devised which is capable of unlocking the bolt to allow its actuation by the renter of the compartment by means of his key.